Comparative analysis of European vertical landing reusable first stage concepts

Kurzfassung

Reusable launch systems have the potential to significantly impact the space launch service market if both a high reliability and low refurbishment costs can be achieved. This study delves into the Vertical Takeoff and Vertical Landing (VTVL) methodology, as currently employed by SpaceX, and forms a segment of the ENTRAIN study by DLR. This broader study encompasses an examination of both Vertical Takeoff Horizontal Landing (VTHL) and VTVL reusable first stages, exploring their performance across high-level design parameters. This manuscript's primary objective is to assess the quantitative impact of high-level design factors on launch vehicle performance, particularly in relation to the development of a future European reusable launch system featuring a VTVL first stage. For a two-stage vehicle with a payload performance of 7.5t into GTO, the effect of varying propellant combinations, staging velocities and engine cycles are assessed. The study encompasses an iterative, multidisciplinary analysis and sizing process for ten different configurations. Each design iteration not only entails a structural design analysis but also includes optimization of the ascent and descent trajectories. Finally, the developed vehicle concepts are compared to derive quantitative insights into the trade-offs associated with key design choices.